package com.atguigu.tree;

/**
 * description:
 * Created by 才睡醒 on 2021-07-15
 */
public class BinaryTreeDemo {
    public static void main(String[] args) {
        //先需要创建一颗二叉树
        BinaryTree binaryTree = new BinaryTree();
        //创建需要的节点
        HeroNode root = new HeroNode(1, "宋江");
        HeroNode node2 = new HeroNode(2, "无用");
        HeroNode node3 = new HeroNode(3, "卢俊义");
        HeroNode node4 = new HeroNode(4, "林冲");
        HeroNode node5 = new HeroNode(5, "关胜");
        //说明，先手动创建二叉树,后面以递归方式创建
        root.setLeft(node2);
        root.setRight(node3);
        node3.setRight(node4);
        node3.setLeft(node5);
        binaryTree.setRoot(root);
        System.out.println("前序");
        binaryTree.preOrder();
        System.out.println("中序");
        binaryTree.infixOrder();
        System.out.println("后序");
        binaryTree.postOrder();
        System.out.println("前序查找");
        HeroNode heroNode = binaryTree.preOrderSerach(5);
        System.out.println(heroNode);

    }
}

//定义二叉树
class BinaryTree {
    private HeroNode root;

    public void setRoot(HeroNode root) {
        this.root = root;
    }

    //前序遍历
    public void preOrder() {
        if (this.root != null) {
            this.root.preOrder();
        } else {
            System.out.println("二叉树为空，无法遍历");
        }
    }

    //中序遍历
    public void infixOrder() {
        if (this.root != null) {
            this.root.infixOrder();
        } else {
            System.out.println("二叉树为空，无法遍历");
        }
    }

    //后序遍历
    public void postOrder() {
        if (this.root != null) {
            this.root.postOrder();
        } else {
            System.out.println("二叉树为空，无法遍历");
        }
    }

    //前序遍历查找
    public HeroNode preOrderSerach(int no) {
        if (this.root != null) {
            return this.root.preOrderSearch(no);
        } else {
            System.out.println("无法查找");
            return null;
        }
    }
}

//先创建HeroNode结点
class HeroNode {
    private int no;
    private String name;
    private HeroNode left;  //默认null
    private HeroNode right;  //默认null

    public HeroNode(int no, String name) {
        this.no = no;
        this.name = name;
    }

    public int getNo() {
        return no;
    }

    public void setNo(int no) {
        this.no = no;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public HeroNode getLeft() {
        return left;
    }

    public void setLeft(HeroNode left) {
        this.left = left;
    }

    public HeroNode getRight() {
        return right;
    }

    public void setRight(HeroNode right) {
        this.right = right;
    }

    @Override
    public String toString() {
        return "HeroNode{" +
                "no=" + no +
                ", name='" + name + '\'' +
                '}';
    }

    //前序遍历
    public void preOrder() {
        System.out.println(this); //先输出父结点
        //递归向左子树前序遍历
        if (this.left != null) {
            this.left.preOrder();
        }
        //递归像右子树前序遍历
        if (this.right != null) {
            this.right.preOrder();
        }
    }

    //中序遍历
    public void infixOrder() {
        //递归像左子树中序遍历
        if (this.left != null) {
            this.left.infixOrder();
        }
        //输出父节点
        System.out.println(this);
        //递归向右子树中序遍历
        if (this.right != null) {
            this.right.infixOrder();
        }
    }

    //后序遍历
    public void postOrder() {
        if (this.left != null) {
            this.left.postOrder();
        }
        if (this.right != null) {
            this.right.postOrder();
        }
        System.out.println(this);
    }

    //前序遍历查找

    /**
     * @param no 查找no
     * @return 如果找到就返回该no, 如果没有找到返回null
     */
    public HeroNode preOrderSearch(int no) {
        System.out.println("进入前序遍历");

        //比较当前节点是不是
        if (this.no == no) {
            return this;
        }
        //1.判断当前节点的左子节点是否为空，如果不为空，则递归前序查找
        //2.如果左递归前序查找，找到结点，则返回
        HeroNode resNode = null;
        if (this.left != null) {
            resNode = this.left.preOrderSearch(no);
        }
        if (resNode != null) {//说明左子树找到
            return resNode;
        }
        //判断当前节点右子节点是否为空，不为空继续查找
        if (this.right != null) {
            resNode = this.right.preOrderSearch(no);
        }
        return resNode;
    }

    //中序遍历查找

    /**
     * @param no 查找no
     * @return 如果找到就返回该no, 如果没有找到返回null
     */
    public HeroNode infixOrderSearch(int no) {

        //1.判断当前节点的左子节点是否为空，如果不为空，则递归前序查找
        //2.如果左递归前序查找，找到结点，则返回
        HeroNode resNode = null;
        if (this.left != null) {
            resNode = this.left.infixOrderSearch(no);
        }
        if (resNode != null) {//说明左子树找到
            return resNode;
        }

        //比较当前节点是不是
        if (this.no == no) {
            return this;
        }

        //判断当前节点右子节点是否为空，不为空继续查找
        if (this.right != null) {
            resNode = this.right.infixOrderSearch(no);
        }
        return resNode;
    }

    //后序遍历查找

    /**
     * @param no 查找no
     * @return 如果找到就返回该no, 如果没有找到返回null
     */
    public HeroNode postOrdersearch(int no) {

        //1.判断当前节点的左子节点是否为空，如果不为空，则递归前序查找
        //2.如果左递归前序查找，找到结点，则返回
        HeroNode resNode = null;
        if (this.left != null) {
            resNode = this.left.postOrdersearch(no);
        }
        if (resNode != null) {//说明左子树找到
            return resNode;
        }

        //判断当前节点右子节点是否为空，不为空继续查找
        if (this.right != null) {
            resNode = this.right.postOrdersearch(no);
        }
        //比较当前节点是不是
        if (this.no == no) {
            return this;
        }
        return resNode;
    }
}
